clang-format: [JS] handle let (ES6).

[mprobst]

Summary

clang-format: [JS] handle let (ES6).

[djasper]

lib/Format/TokenAnnotator.cpp

2087

Hm.. Or Line.First->isOneOf(Keywords.kw_var, KeyWords.kw_let).

I like that a bit better, but don't really care.

[mprobst]

Use isOneOf instead of startsWith.

[djasper]

Submitted as r248713.

lib/Format/FormatToken.h

AdditionalKeywords(IdentifierTable &IdentTable) {
     kw_CF_ENUM = &IdentTable.get("CF_ENUM");
     kw_CF_OPTIONS = &IdentTable.get("CF_OPTIONS");
     kw_NS_ENUM = &IdentTable.get("NS_ENUM");
     kw_NS_OPTIONS = &IdentTable.get("NS_OPTIONS");
 
     kw_finally = &IdentTable.get("finally");
     kw_function = &IdentTable.get("function");
     kw_import = &IdentTable.get("import");
+    kw_let = &IdentTable.get("let");
     kw_var = &IdentTable.get("var");
 
     kw_abstract = &IdentTable.get("abstract");
     kw_assert = &IdentTable.get("assert");
     kw_extends = &IdentTable.get("extends");
     kw_implements = &IdentTable.get("implements");
     kw_instanceof = &IdentTable.get("instanceof");
     kw_interface = &IdentTable.get("interface");
struct AdditionalKeywords {
   IdentifierInfo *kw_NS_ENUM;
   IdentifierInfo *kw_NS_OPTIONS;
   IdentifierInfo *kw___except;
 
   // JavaScript keywords.
   IdentifierInfo *kw_finally;
   IdentifierInfo *kw_function;
   IdentifierInfo *kw_import;
+  IdentifierInfo *kw_let;
   IdentifierInfo *kw_var;
 
   // Java keywords.
   IdentifierInfo *kw_abstract;
   IdentifierInfo *kw_assert;
   IdentifierInfo *kw_extends;
   IdentifierInfo *kw_implements;
   IdentifierInfo *kw_instanceof;

lib/Format/TokenAnnotator.cpp

if (Style.Language == FormatStyle::LK_Cpp) {
     if (Right.is(tok::period) &&
         Left.isOneOf(Keywords.kw_optional, Keywords.kw_required,
                      Keywords.kw_repeated))
       return true;
     if (Right.is(tok::l_paren) &&
         Left.isOneOf(Keywords.kw_returns, Keywords.kw_option))
       return true;
   } else if (Style.Language == FormatStyle::LK_JavaScript) {
-    if (Left.isOneOf(Keywords.kw_var, TT_JsFatArrow))
+    if (Left.isOneOf(Keywords.kw_let, Keywords.kw_var, TT_JsFatArrow))
       return true;
     if (Right.isOneOf(TT_JsTypeColon, TT_JsTypeOptionalQuestion))
       return false;
     if ((Left.is(tok::l_brace) || Right.is(tok::r_brace)) &&
         Line.First->isOneOf(Keywords.kw_import, tok::kw_export))
       return false;
     if (Left.is(tok::ellipsis))
       return false;
if (Style.Language == FormatStyle::LK_JavaScript) {
     // FIXME: This might apply to other languages and token kinds.
     if (Right.is(tok::char_constant) && Left.is(tok::plus) && Left.Previous &&
         Left.Previous->is(tok::char_constant))
       return true;
     if (Left.is(TT_DictLiteral) && Left.is(tok::l_brace) && Line.Level == 0 &&
         Left.Previous && Left.Previous->is(tok::equal) &&
         Line.First->isOneOf(tok::identifier, Keywords.kw_import, tok::kw_export,
                             tok::kw_const) &&
-        // kw_var is a pseudo-token that's a tok::identifier, so matches above.
-        !Line.startsWith(Keywords.kw_var))
+        // kw_var/kw_let are pseudo-tokens that are tok::identifier, so match
+        // above.
+        !Line.startsWith(Keywords.kw_var) && !Line.startsWith(Keywords.kw_let))
       // Object literals on the top level of a file are treated as "enum-style".
       // Each key/value pair is put on a separate line, instead of bin-packing.
       return true;
     if (Left.is(tok::l_brace) && Line.Level == 0 &&
         (Line.startsWith(tok::kw_enum) ||
          Line.startsWith(tok::kw_export, tok::kw_enum)))
       // JavaScript top-level enum key/value pairs are put on separate lines
       // instead of bin-packing.

lib/Format/UnwrappedLineParser.cpp

void UnwrappedLineParser::parseJavaScriptEs6ImportExport() {
   // Consume "function" and "default function", so that these get parsed as
   // free-standing JS functions, i.e. do not require a trailing semicolon.
   if (FormatTok->is(Keywords.kw_function)) {
     nextToken();
     return;
   }
 
   if (FormatTok->isOneOf(tok::kw_const, tok::kw_class, tok::kw_enum,
-                         Keywords.kw_var))
+                         Keywords.kw_let, Keywords.kw_var))
     return; // Fall through to parsing the corresponding structure.
 
   if (FormatTok->is(tok::l_brace)) {
     FormatTok->BlockKind = BK_Block;
     parseBracedList();
   }
 
   while (!eof() && FormatTok->isNot(tok::semi) &&

unittests/Format/FormatTestJS.cpp

 }
 
 TEST_F(FormatTestJS, LiteralOperatorsCanBeKeywords) {
   verifyFormat("not.and.or.not_eq = 1;");
 }
 
 TEST_F(FormatTestJS, ES6DestructuringAssignment) {
   verifyFormat("var [a, b, c] = [1, 2, 3];");
+  verifyFormat("let [a, b, c] = [1, 2, 3];");
   verifyFormat("var {a, b} = {a: 1, b: 2};");
+  verifyFormat("let {a, b} = {a: 1, b: 2};");
 }
 
 TEST_F(FormatTestJS, ContainerLiterals) {
   verifyFormat("var x = {y: function(a) { return a; }};");
   verifyFormat("return {\n"
                "  link: function() {\n"
                "    f();  //\n"
                "  }\n"